The present invention relates generally to viscous material dispensing systems or apparatus, such as, for example, systems or apparatus for dispensing and distributing adhesive or resin materials, and more particularly to a die plate which is adapted to be incorporated within the system or apparatus wherein the die plate is provided with structural means which permits the die plate to be rapidly and easily mounted upon and removed from, for example, the operatively associated glue block or adhesive manifold.
Various viscous material dispensing systems or apparatus, such as, for example, systems or apparatus for dispensing and distributing adhesive or resin materials, whereby the adhesive or resin materials can be applied to or deposited upon a particular substrate, are of course well known. One such known system or apparatus is disclosed within U.S. Pat. No. 5,622,315 which was issued on Apr. 22, 1997 to the inventors Keane et al. As shown in FIG. 6 of the patent, the system or apparatus comprises an upper die half 12, a lower die half 14, a mouthpiece or die plate 22, and a shim 16 which is interposed between and separates the upper and lower die halves 12, 14 so as to define a die opening 20 therebetween. The mouthpiece or die plate 22 is secured to the upper die half 12 by means of a plurality of threaded screws 124.
Another material dispensing system or apparatus for likewise dispensing and distributing materials of the aforenoted type for deposition upon a substrate is disclosed within U.S. Pat. No. 5,478,224 which was issued on Dec. 26, 1995 to the inventor McGuffey, such patent being assigned to the assignee of the present invention. As best appreciated from FIGS. 2 and 3 of the patent, the system or apparatus similarly comprises a glue block or adhesive manifold 66, a mouthpiece or die plate 86, and a shim 88 interposed between the bottom surface of the glue block or adhesive manifold 66 and the mouthpiece or die plate 86. A plurality of fasteners, illustrated but not numbered, fixedly secure the mouthpiece or die plate 86, and the shim 88, upon the underside of the glue block or adhesive manifold 66.
FIG. 1 is also illustrative of a conventionally known die plate generally indicated by the reference character 10. As is known, the die plate 10 comprises a plurality of laterally spaced material or fluid deposition channels 12, into which, for example, the viscous fluid or material is initially charged or deposited, and a laterally extending distribution channel 14 which fluidically interconnects the plurality of fluid deposition channels 12. A doctor blade or material application surface 16 is formed upon a leading edge portion of the die plate 10, and a recessed lip region 18 is defined within the leading edge portion of the die plate 10 so as to permit defined or precisely controlled fluidic communication between the laterally extending distribution channel 14 and the doctor blade or material application surface 16. A plurality of through bores 20 are defined within the die plate 10 so as to permit the die plate 10 to be fixedly secured to a glue block, adhesive manifold, or the like, by means of suitable threaded bolt fasteners, or the like, not shown.
FIG. 2 illustrates another conventionally known die plate which is similar to the die plate 10 of FIG. 1 and is generally indicated by the reference character 110. In view of the similarity of the die plate 110 of FIG. 2 to the die plate 10 of FIG. 1, like or corresponding parts of the die plate 110 have been designated by similar reference characters, within the 100 series, however, further detailed description of the same has been omitted herefrom in view of the fact that one of ordinary skill in the art will readily appreciate the various similar operative components or elements of the die plate 110.
In view of the threaded bolt fastening of the various die plates, or the like, to the associated support structures as disclosed within the patents of Keane et al. and McGuffey, as well as the die plates 10 and 110 illustrated in FIGS. 1 and 2, and in particular, as illustrated in FIGS. 2B and 3 of Keane et al. and McGuffey, respectively, it is readily appreciated that the number of bolt fasteners 124, for example, as shown in Keane et al., as well as those not numbered in McGuffey, which are used to fasten the die plates or the like to their support structures, is considerable. Accordingly, when a particular die plate is to be exchanged or replaced so as to, for example, alter the adhesive patterns or replace a worn die, the exchange or replacement operation is quite time-consuming and labor intensive in view of the considerable number of bolt fasteners which are required to be completely removed from the support structure in connection with the removal of the particular or original die plate, and subsequently, the replacement or reinsertion of such bolt fasteners back into the support structure in order to secure the newly exchanged or replacement die plate upon the support structure.
FIGS. 3 and 4 illustrate another conventional die plate assembly system or apparatus, manufactured by the NORDSON CORPORATION, which was designed to overcome the operative drawbacks characteristic of the die plates illustrated within FIGS. 1 and 2, as well as those illustrated within the foregoing patents to Keane et al. and McGuffey. More particularly, with reference initially being made to FIG. 3, such apparatus or system 210 is seen to comprise a head 212 within which is mounted a cartridge heater 214. An adhesive manifold 216, through which a supply of adhesive 218 is conveyed, is mounted upon the head 212, and a doctor blade assembly 220, which is shown enlarged in FIG. 4, is adapted to be mounted upon the head 212. As shown in FIG. 4, the doctor blade assembly 220 comprises a pair of doctor blades 222,224 between which is mounted a shim 226, the doctor blades 222,224 being fixedly secured together by means of a threaded fastener 228. In order to mount the doctor blade assembly 220 upon the head 212, a substantially C-shaped clamp 230 is bolted to head 212 by means of one or more bolt fasteners 232. Consequently, as may be appreciated from FIG. 3, the doctor blade assembly 220 is clamped between a lower leg portion 234 of the C-clamp 230 and a lower dependent portion 236 of the head 212. Accordingly, when it is desired to remove or exchange the die in order to change the adhesive patterns or replace a worn die, the one or more bolt fasteners 232 are simply loosened, but not removed, and the doctor blade assembly 220 is thereby permitted to be readily, simply, and quickly removed, and a new doctor blade assembly 220 is likewise able to be readily, simply, and quickly inserted. Bolt fasteners 232 are then re-tightened and the system or apparatus is back on line.
While the aforenoted NORDSON system thus overcomes the operative drawbacks characteristic of the prior art of Keane et al. and McGuffey, as well as the die plates 10 and 110 shown in FIGS. 1 and 2, in that the doctor blade assembly can be easily and rapidly exchanged or replaced without operator personnel having to perform the aforenoted time-consuming and tedious operations of completely removing the bolt fasteners mounting the die plates upon the support structure, the NORDSON system or apparatus exhibits its own operative drawbacks and has therefore not proven to be entirely satisfactory. For example, in view of the fact that the doctor blade assembly 220 is clamped between the C-clamp 230 and the head 212, as opposed to being bolted upon the head 212, the doctor blade assembly 220 may not be precisely positioned or oriented upon the head 212 whereby the resulting adhesive patterns, to be applied to a particular substrate, may not be achieved. In addition, if the doctor blade assembly 220 is not precisely or properly positioned or oriented upon the head 212, the conveyed adhesive 218 will, for example, become interposed, or penetrate the surface interface defined, between the doctor blade assembly 220 and the lower end or dependent portion 236 of the head 212 whereby, again, proper dispensing, application, or distribution of the adhesive onto or upon the substrate will be adversely affected.
Accordingly, there is a need in the art for a new and improved die plate or shim element or component whereby all of the aforenoted drawbacks and disadvantages characteristic of the prior art die plate or shim assemblies can be overcome or rectified.
Accordingly, it is an object of the present invention to provide a new and improved die plate or shim element or component and a method of mounting the same upon associated support structure of fluid medium dispensing apparatus.
Another object of the present invention is to provide a new and improved die plate or shim element or component which enables the same to be precisely, yet adjustably, positioned upon the support structure of the fluid medium dispensing apparatus.
A further object of the present invention is to provide a new and improved die plate or shim element or component which enables the same to be quickly and easily mounted upon or removed from the support structure of the fluid medium dispensing apparatus.
The foregoing and other objects are achieved in accordance with the teachings of the present invention through the provision of a new and improved die plate or shim element or component wherein the die plate or shim element or component comprises an elongated member having a longitudinal extent. A plurality of through-bores are provided within the die plate or shim element or component so as to be substantially equally spaced along the longitudinal extent thereof and within or through which fastener shank portions can extend so as to facilitate the mounting of the die plate or shim element or component upon a suitable support or mounting surface of the fluid medium dispensing apparatus.
In accordance with the particularly new and novel features of the present invention, milled slots are formed within the die plate or shim so as to extend inwardly, in directions perpendicular to the longitudinal extent of the die plate or shim, from the free edge of the die plate or shim which is oppositely disposed with respect to the doctor blade or fluid medium application surface, so as to mate with or intersect the through-bores which are conventionally provided within the die plate or shim. In this manner, when, for example, the die plate or shim is to be removed from the support or mounting surface of the fluid medium dispensing apparatus, the threaded bolt or screw fasteners need only be loosened, and not removed, whereby the die plate or shim can simply be slidably removed from the support or mounting surface as a result of the fastener shank portions being, in effect, slid through the milled slots of the die plate or shim. In a similar manner, a new die plate or shim can be mounted upon the support or mounting surface of the dispensing apparatus by aligning the milled slots of the new die plate or shim with the fastener shank portions of the fasteners still threadedly engaged within the support or mounting surface of the fluid medium dispensing apparatus and then sliding the die plate or shim onto the support or mounting surface of the fluid medium dispensing apparatus such that the shank portions of the threaded fasteners enter the milled slots of the die plate or shim. Once the new die plate or shim is properly positioned upon the support or mounting surface of the dispensing apparatus as a result of the fastener shank portions being, in effect, seated or coaxially aligned with the through-bores of the die plate or shim, the threaded fasteners are re-tightened so as to fixedly secure the die plate or shim upon the support or mounting surface of the dispensing apparatus.
In accordance with a further feature of the present invention die plate or shim, the through-bores of the shim or die plate have unconventional oval-shaped cross-sectional configurations such that together with the milled slots, the combined slot-bore structure has a substantially key-hole shaped configuration. Such structure permits the die plate or shim to experience movement with two degrees of freedom, in opposite lateral directions aligned with the longitudinal extent of the die plate or shim, with respect to the threaded fasteners such that positional adjustment of, for example, the die plate can be achieved in order to slightly alter the precise positions at which the fluid medium is being discharged, dispensed, or deposited. Alternatively, or additionally, the provision of such degrees of freedom of movement of the die plate or shim facilitates the mounting or positional adjustment of the die plate or shim upon the support surface of the dispensing apparatus when, for example, the die plate or shim may exhibit dimensional inconsistencies, or may experience different growth rates, relative to the heated head or manifold of the dispensing apparatus, due to being fabricated from materials which are different from those of the head or manifold wherein such materials exhibit or are characterized by different coefficients of expansion.